JPH03283325A - Formation of caulking receive metal mold of head portion of rivet type electric contact - Google Patents

Abstract

PURPOSE:To prevent the inner peripheral face of a mortar-shaped recessed portion from being torn off by subjecting to specular finishing the surface and the outside end face of the projecting portion of a male mold formed with super hardness, and forming a Ti film through wet plating, and pressing the protecting portion of the male mold into a metal mold material to form the mortar-shaped recessed portion. CONSTITUTION:The surface and the outside end face 7b of the projecting portion 7a of a male mold 7 formed with super hardness are subjected to specular finishing and then a Ti film 10 is formed by sputtering and the projecting portion 7a of the male mold 7 is pressed into a metal mold material 11 to fabricate a caulking receive metal mold 5 having a mortar shaped recessed portion 5a and the metal mold 5 is subjected to quenching process and the mortar-shaped recessed portion 5a is subjected to polish finishing. Friction resistance between the Ti film 10 and the metal mold material 11 is decreased by the lubricating characteristic of the Ti film 10 and the inside face of the mortar-shaped recessed portion 5a molded is smoothly finished. The mortar-shaped recessed portion 5a is thus prevented from being torn off.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention mainly relates to a method for making a crimping receiving mold for the head of a rivet-type electrical contact, and particularly to a method for making a mold for crimping the head of a rivet-type electrical contact, and particularly for determining the finished state of the inner surface of the mouth-shaped recess of the mold. Regarding how to make it better.

(Prior Art) Conventionally, in order to make an electrical contact 4 in which a rivet-type electrical contact is attached to a contact mounting hole 3 of a spring base 2 as shown in FIG. 2, a rivet-type electrical contact as shown in FIG. The head 1a of the electrical contact 1 is inserted into the mouth-shaped recess 5a of the caulking receiving mold 5, and the leg 1b inserted into the contact attachment hole 3 of the spring base material 2 is crushed with a caulking punch 6 to form the periphery of the contact attachment hole 3. It's stiff.

The mouth-shaped recess 5a of the caulking receiving mold 5 used in manufacturing the electric contact 4 was manufactured by electrical discharge machining or press-fitting of a male mold.

(Problem to be solved by the invention) By the way, manufacturing by electrical discharge machining is expensive, so
Generally, as shown in Fig. 4, a convex portion 7a of a male mold 7, which is slightly smaller than the head shape of a rivet type electrical contact, is press-fitted into a mold material made of SK material to form a caulking receiving mold having a mouth-shaped recess 5a. 5, but when the male mold 7 is press-fitted, if the taper angle is 8 degrees or less or the depth of the mouth-shaped recess 5a is 1 mm or more, the male mold 7 and the material are attached to the upper part of the inner peripheral surface of the mouth-shaped recess 5a. The friction causes peeling 8 as shown in FIG. hole 3
When the leg portion ib inserted through is crushed with the caulking punch 6 and caulked to the periphery of the contact mounting hole 3, the contact head 1a of the electric contact 4 will not be separated from the mouth-shaped recess 5a of the caulking receiving mold 5. This occurred frequently, and when the spring base material 2 was pulled up, as shown in Fig. 6 (the spring base material 2 was bent or could not be removed).

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for producing a caulking receiving mold without causing tearing on the inner circumferential surface of the mouth-shaped recess.

(Means for Solving the Problems) In order to solve the above-mentioned problems, a method for creating a caulking receiving mold for a rivet-type electrical contact head according to the present invention is directed to After mirror-finishing the outer tip surface, a Ti film is formed by dry plating, and the protrusion of this male mold is press-fitted into the mold material to form a mortar-shaped recess to create a caulking receiving mold. It is something to do.

(Function) As described above, the method for creating a caulking receiver mold of the present invention involves press-fitting a male convex portion having a mirror-finished convex surface and a Ti film formed on its outer tip surface into a mold material. from,
Due to the lubricating properties of the Ti film, the frictional resistance with the mold material is reduced, and the inner surface of the mouth-shaped recess to be molded is finished smoothly without any peeling.

In addition, the thickness of the Ti film is 5 to IO from the point of view of lubricity and dimensional accuracy.
μm is preferred.

(Example) An example of the method for making a rivet-type electric contact head crimping receiver mold of the present invention will be described with reference to figures.As shown in Figure 1a, the mold is made of carbide and has a diameter of 18+ nm and a height of 40
The height is 1 on the outer peripheral surface of the taper angle lO° in the male die 7 of mm.
After mirror-finishing the surface of the convex portion 7a with a diameter of 4 mm and its outer tip surface 7b, a 7 μm thick Ti film 10 was formed by sputtering as shown in FIG. As shown in Fig. 1C, it is press-fitted into a mold material 11 made of <5KD-11 with a diameter of 18 mm and a height of 10 mm, and an opening in the center with a diameter of 4.05 mm and a depth of 1 is made as shown in Fig. 1D.
mm, taper angle of inner peripheral surface lO°, bottom circumference 0.4mmR
A caulking receiving mold 5 having a mouth-shaped recess 5a was manufactured, and then hardened, and the mouth-shaped recess 5a was polished.

The caulking receiving mold 5 and the convex portion 7 of the example thus created
A mouth-shaped recess 5a was formed in each of 20 conventional caulking receiver molds 5, which were made in the same manner as in the example using the male mold 7 whose surface a and its outer tip surface 7b were mirror-finished and no Ti film was formed. When inspected, there were 5 cases in which peeling had occurred on the inner circumferential surface of the conventional example, but none in the example.

Then, as shown in FIG. 3, the head 1a of the rivet-type electric contact l is inserted into the mouth-shaped recess 5a where peeling has occurred on the inner peripheral surface of the conventional caulking receiving mold 5, and the contact mounting hole 3 of the spring base material 2 is inserted. After crushing the leg portion 1b inserted through the crimping punch 6 and crimping it around the periphery of the contact mounting hole 3 to make the electric contact 4 shown in FIG. 2, when the spring base material 2 is pulled up, as shown in FIG. As shown in the figure, the spring base material 2 was bent and the contact head 1a could not be removed.

On the other hand, after making the electrical contact 4 shown in FIG. 2 in the same manner using the mouth-shaped recess 5 that does not cause peeling on the inner peripheral surface of the caulking receiving mold 5 of the example, the spring base material 2 was pulled up. When the spring base 2 does not bend as shown in Figure 6 (the contact head 1a
was removed smoothly.

(Effects of the Invention) As can be seen from the above explanation, according to the method for creating a caulking receiver mold for the head of a rivet-type electrical contact according to the present invention, tearing does not occur in the mouth-shaped recess, and therefore, the head of the rivet-type electrical contact When an electric contact is made by accepting the contact head and crushing the leg inserted into the contact mounting hole of the spring base material, it has the excellent effect of creating a caulking receiving mold from which the contact head can be removed smoothly.

[Brief explanation of the drawing]

Figures 1a to d are diagrams showing a method for making a caulking receiver mold for a rivet-type electric contact head of the present invention, Figure 2 is a diagram showing an electric contact, and Figure 3 is a diagram showing a method for manufacturing an electric contact. Figure 4 is a diagram showing a conventional manufacturing method for a caulking receiver mold for a rivet-type electric contact head, and Figure 5 is a diagram showing a caulking receiver with peeling on the inner peripheral surface of the mouth shape due to the manufacturing method. FIG. 6, a diagram showing the mold, is a diagram showing the bending of the spring base material when the spring base material is pulled up after manufacturing an electric contact using the caulking receiving mold shown in FIG. 5. 5... Caulking receiving mold, 5a... Mouth-shaped recess, 7...
・Male mold, 7a...Protrusion, 7b...Outside tip surface of the protrusion, IO...Ti film, 11...Mold material.

Claims (1)

[Claims] 1) After mirror-finishing the surface of the convex part of the male mold made of carbide and its outer tip surface, a Ti film is formed by dry plating, and the convex part of the male mold is press-fitted into the mold material. A method for making a caulking receiver mold for a rivet-type electric contact head, which comprises forming a mortar-shaped recess and making a caulking receiver mold.